Shadow Prophecy

In Commander, Shadow Prophecy fits any black-blue shell that wants flexible, scalable card draw — pay two in the early game for modest selection, sink ten mana into it late to rifle through your deck and pick your two best answers. Pauper is where it competes hardest for a slot, since the format's card draw options are constrained by rarity and a two-mana floor is real; it earns inclusion there in control builds that can take advantage of the instant speed. In older, more powerful formats like Legacy and Vintage, the rate simply doesn't compete with cantrips and draw spells that cost one mana or less, so Shadow Prophecy rarely sees play there. Modern and Pioneer sit in between — the card is legal but blue has access to strict upgrades at every point on the curve, so it mostly stays in the bulk bin.